<template>
    <div>
        <h1>当前求和为:{{ sum }}</h1>
        <h3>当前求和放大为：{{ bigSum}}</h3>
        <h3>我在{{ school }},学习{{ subject }}</h3>
        <select v-model.number="n"><!-- 写冒号:value和.number都能为数字类型 -->
            <option :value="1">1</option>
            <option :value="2">2</option>
            <option :value="3">3</option>
        </select>
        <button @click="increment">+</button>
        <button @click="decrement">-</button>
        <button @click="incrementOdd">当前求和为奇数再加</button>
        <button @click="incrementWait">等一等再加</button>
    </div>
</template>

<script>
import { mapState,mapGetters } from 'vuex'
export default {
name:'Count',
data(){
        return {
            n:1,//用户选择的数字
        }
    },
    computed:{
        //靠程序员自己写计算属性
       /*  sum(){return this.$store.state.sum},
        school(){return this.$store.state.school},
        subject(){return this.$store.state.subject}, */

        //借助mapState生成计算属性，从state中读取数据（对象写法）
        ...mapState({sum:'sum',school:'school',subject:'subject'}),//说明这个是对象
        // 借助mapState生成计算属性，从state中读取数据（数组写法）
        ...mapState(['sum','school','subject']),


        // bigSum(){return this.$store.getters.bigSum}
         //借助mapGetters生成计算属性，从Getters中读取数据（对象写法）
        ...mapGetters({bigSum:'bigSum'}),
        // ...mapGetters(['bigSum'])//数组写法

    },
    methods:{
        increment(){
           this.$store.commit('JIA',this.n)//更改形式,直接越过actions,找mutations
        },
        decrement(){
            this.$store.commit('JIAN',this.n)//直接越过actions,找mutations
        },
        incrementOdd(){
            this.$store.dispatch('jiaOdd',this.n)     
        },
        incrementWait(){
                this.$store.dispatch('jiaWait',this.n)
        }
    }
}
</script>

<style>
button{
    margin: 0 10px;
}
</style>